get_repo_path: refactor path-allocation
[git] / builtin / clone.c
1 /*
2  * Builtin "git clone"
3  *
4  * Copyright (c) 2007 Kristian Høgsberg <krh@redhat.com>,
5  *               2008 Daniel Barkalow <barkalow@iabervon.org>
6  * Based on git-commit.sh by Junio C Hamano and Linus Torvalds
7  *
8  * Clone a repository into a different directory that does not yet exist.
9  */
10
11 #include "builtin.h"
12 #include "lockfile.h"
13 #include "parse-options.h"
14 #include "fetch-pack.h"
15 #include "refs.h"
16 #include "tree.h"
17 #include "tree-walk.h"
18 #include "unpack-trees.h"
19 #include "transport.h"
20 #include "strbuf.h"
21 #include "dir.h"
22 #include "sigchain.h"
23 #include "branch.h"
24 #include "remote.h"
25 #include "run-command.h"
26 #include "connected.h"
27
28 /*
29  * Overall FIXMEs:
30  *  - respect DB_ENVIRONMENT for .git/objects.
31  *
32  * Implementation notes:
33  *  - dropping use-separate-remote and no-separate-remote compatibility
34  *
35  */
36 static const char * const builtin_clone_usage[] = {
37         N_("git clone [<options>] [--] <repo> [<dir>]"),
38         NULL
39 };
40
41 static int option_no_checkout, option_bare, option_mirror, option_single_branch = -1;
42 static int option_local = -1, option_no_hardlinks, option_shared, option_recursive;
43 static char *option_template, *option_depth;
44 static char *option_origin = NULL;
45 static char *option_branch = NULL;
46 static const char *real_git_dir;
47 static char *option_upload_pack = "git-upload-pack";
48 static int option_verbosity;
49 static int option_progress = -1;
50 static struct string_list option_config;
51 static struct string_list option_reference;
52 static int option_dissociate;
53
54 static struct option builtin_clone_options[] = {
55         OPT__VERBOSITY(&option_verbosity),
56         OPT_BOOL(0, "progress", &option_progress,
57                  N_("force progress reporting")),
58         OPT_BOOL('n', "no-checkout", &option_no_checkout,
59                  N_("don't create a checkout")),
60         OPT_BOOL(0, "bare", &option_bare, N_("create a bare repository")),
61         OPT_HIDDEN_BOOL(0, "naked", &option_bare,
62                         N_("create a bare repository")),
63         OPT_BOOL(0, "mirror", &option_mirror,
64                  N_("create a mirror repository (implies bare)")),
65         OPT_BOOL('l', "local", &option_local,
66                 N_("to clone from a local repository")),
67         OPT_BOOL(0, "no-hardlinks", &option_no_hardlinks,
68                     N_("don't use local hardlinks, always copy")),
69         OPT_BOOL('s', "shared", &option_shared,
70                     N_("setup as shared repository")),
71         OPT_BOOL(0, "recursive", &option_recursive,
72                     N_("initialize submodules in the clone")),
73         OPT_BOOL(0, "recurse-submodules", &option_recursive,
74                     N_("initialize submodules in the clone")),
75         OPT_STRING(0, "template", &option_template, N_("template-directory"),
76                    N_("directory from which templates will be used")),
77         OPT_STRING_LIST(0, "reference", &option_reference, N_("repo"),
78                         N_("reference repository")),
79         OPT_BOOL(0, "dissociate", &option_dissociate,
80                  N_("use --reference only while cloning")),
81         OPT_STRING('o', "origin", &option_origin, N_("name"),
82                    N_("use <name> instead of 'origin' to track upstream")),
83         OPT_STRING('b', "branch", &option_branch, N_("branch"),
84                    N_("checkout <branch> instead of the remote's HEAD")),
85         OPT_STRING('u', "upload-pack", &option_upload_pack, N_("path"),
86                    N_("path to git-upload-pack on the remote")),
87         OPT_STRING(0, "depth", &option_depth, N_("depth"),
88                     N_("create a shallow clone of that depth")),
89         OPT_BOOL(0, "single-branch", &option_single_branch,
90                     N_("clone only one branch, HEAD or --branch")),
91         OPT_STRING(0, "separate-git-dir", &real_git_dir, N_("gitdir"),
92                    N_("separate git dir from working tree")),
93         OPT_STRING_LIST('c', "config", &option_config, N_("key=value"),
94                         N_("set config inside the new repository")),
95         OPT_END()
96 };
97
98 static const char *argv_submodule[] = {
99         "submodule", "update", "--init", "--recursive", NULL
100 };
101
102 static const char *get_repo_path_1(struct strbuf *path, int *is_bundle)
103 {
104         static char *suffix[] = { "/.git", "", ".git/.git", ".git" };
105         static char *bundle_suffix[] = { ".bundle", "" };
106         size_t baselen = path->len;
107         struct stat st;
108         int i;
109
110         for (i = 0; i < ARRAY_SIZE(suffix); i++) {
111                 strbuf_setlen(path, baselen);
112                 strbuf_addstr(path, suffix[i]);
113                 if (stat(path->buf, &st))
114                         continue;
115                 if (S_ISDIR(st.st_mode) && is_git_directory(path->buf)) {
116                         *is_bundle = 0;
117                         return path->buf;
118                 } else if (S_ISREG(st.st_mode) && st.st_size > 8) {
119                         /* Is it a "gitfile"? */
120                         char signature[8];
121                         const char *dst;
122                         int len, fd = open(path->buf, O_RDONLY);
123                         if (fd < 0)
124                                 continue;
125                         len = read_in_full(fd, signature, 8);
126                         close(fd);
127                         if (len != 8 || strncmp(signature, "gitdir: ", 8))
128                                 continue;
129                         dst = read_gitfile(path->buf);
130                         if (dst) {
131                                 *is_bundle = 0;
132                                 return dst;
133                         }
134                 }
135         }
136
137         for (i = 0; i < ARRAY_SIZE(bundle_suffix); i++) {
138                 strbuf_setlen(path, baselen);
139                 strbuf_addstr(path, bundle_suffix[i]);
140                 if (!stat(path->buf, &st) && S_ISREG(st.st_mode)) {
141                         *is_bundle = 1;
142                         return path->buf;
143                 }
144         }
145
146         return NULL;
147 }
148
149 static char *get_repo_path(const char *repo, int *is_bundle)
150 {
151         struct strbuf path = STRBUF_INIT;
152         const char *raw;
153         char *canon;
154
155         strbuf_addstr(&path, repo);
156         raw = get_repo_path_1(&path, is_bundle);
157         canon = raw ? xstrdup(absolute_path(raw)) : NULL;
158         strbuf_release(&path);
159         return canon;
160 }
161
162 static char *guess_dir_name(const char *repo, int is_bundle, int is_bare)
163 {
164         const char *end = repo + strlen(repo), *start;
165         size_t len;
166         char *dir;
167
168         /*
169          * Strip trailing spaces, slashes and /.git
170          */
171         while (repo < end && (is_dir_sep(end[-1]) || isspace(end[-1])))
172                 end--;
173         if (end - repo > 5 && is_dir_sep(end[-5]) &&
174             !strncmp(end - 4, ".git", 4)) {
175                 end -= 5;
176                 while (repo < end && is_dir_sep(end[-1]))
177                         end--;
178         }
179
180         /*
181          * Find last component, but be prepared that repo could have
182          * the form  "remote.example.com:foo.git", i.e. no slash
183          * in the directory part.
184          */
185         start = end;
186         while (repo < start && !is_dir_sep(start[-1]) && start[-1] != ':')
187                 start--;
188
189         /*
190          * Strip .{bundle,git}.
191          */
192         strip_suffix(start, is_bundle ? ".bundle" : ".git" , &len);
193
194         if (is_bare)
195                 dir = xstrfmt("%.*s.git", (int)len, start);
196         else
197                 dir = xstrndup(start, len);
198         /*
199          * Replace sequences of 'control' characters and whitespace
200          * with one ascii space, remove leading and trailing spaces.
201          */
202         if (*dir) {
203                 char *out = dir;
204                 int prev_space = 1 /* strip leading whitespace */;
205                 for (end = dir; *end; ++end) {
206                         char ch = *end;
207                         if ((unsigned char)ch < '\x20')
208                                 ch = '\x20';
209                         if (isspace(ch)) {
210                                 if (prev_space)
211                                         continue;
212                                 prev_space = 1;
213                         } else
214                                 prev_space = 0;
215                         *out++ = ch;
216                 }
217                 *out = '\0';
218                 if (out > dir && prev_space)
219                         out[-1] = '\0';
220         }
221         return dir;
222 }
223
224 static void strip_trailing_slashes(char *dir)
225 {
226         char *end = dir + strlen(dir);
227
228         while (dir < end - 1 && is_dir_sep(end[-1]))
229                 end--;
230         *end = '\0';
231 }
232
233 static int add_one_reference(struct string_list_item *item, void *cb_data)
234 {
235         char *ref_git;
236         const char *repo;
237         struct strbuf alternate = STRBUF_INIT;
238
239         /* Beware: read_gitfile(), real_path() and mkpath() return static buffer */
240         ref_git = xstrdup(real_path(item->string));
241
242         repo = read_gitfile(ref_git);
243         if (!repo)
244                 repo = read_gitfile(mkpath("%s/.git", ref_git));
245         if (repo) {
246                 free(ref_git);
247                 ref_git = xstrdup(repo);
248         }
249
250         if (!repo && is_directory(mkpath("%s/.git/objects", ref_git))) {
251                 char *ref_git_git = mkpathdup("%s/.git", ref_git);
252                 free(ref_git);
253                 ref_git = ref_git_git;
254         } else if (!is_directory(mkpath("%s/objects", ref_git)))
255                 die(_("reference repository '%s' is not a local repository."),
256                     item->string);
257
258         if (!access(mkpath("%s/shallow", ref_git), F_OK))
259                 die(_("reference repository '%s' is shallow"), item->string);
260
261         if (!access(mkpath("%s/info/grafts", ref_git), F_OK))
262                 die(_("reference repository '%s' is grafted"), item->string);
263
264         strbuf_addf(&alternate, "%s/objects", ref_git);
265         add_to_alternates_file(alternate.buf);
266         strbuf_release(&alternate);
267         free(ref_git);
268         return 0;
269 }
270
271 static void setup_reference(void)
272 {
273         for_each_string_list(&option_reference, add_one_reference, NULL);
274 }
275
276 static void copy_alternates(struct strbuf *src, struct strbuf *dst,
277                             const char *src_repo)
278 {
279         /*
280          * Read from the source objects/info/alternates file
281          * and copy the entries to corresponding file in the
282          * destination repository with add_to_alternates_file().
283          * Both src and dst have "$path/objects/info/alternates".
284          *
285          * Instead of copying bit-for-bit from the original,
286          * we need to append to existing one so that the already
287          * created entry via "clone -s" is not lost, and also
288          * to turn entries with paths relative to the original
289          * absolute, so that they can be used in the new repository.
290          */
291         FILE *in = fopen(src->buf, "r");
292         struct strbuf line = STRBUF_INIT;
293
294         while (strbuf_getline(&line, in, '\n') != EOF) {
295                 char *abs_path;
296                 if (!line.len || line.buf[0] == '#')
297                         continue;
298                 if (is_absolute_path(line.buf)) {
299                         add_to_alternates_file(line.buf);
300                         continue;
301                 }
302                 abs_path = mkpathdup("%s/objects/%s", src_repo, line.buf);
303                 normalize_path_copy(abs_path, abs_path);
304                 add_to_alternates_file(abs_path);
305                 free(abs_path);
306         }
307         strbuf_release(&line);
308         fclose(in);
309 }
310
311 static void copy_or_link_directory(struct strbuf *src, struct strbuf *dest,
312                                    const char *src_repo, int src_baselen)
313 {
314         struct dirent *de;
315         struct stat buf;
316         int src_len, dest_len;
317         DIR *dir;
318
319         dir = opendir(src->buf);
320         if (!dir)
321                 die_errno(_("failed to open '%s'"), src->buf);
322
323         if (mkdir(dest->buf, 0777)) {
324                 if (errno != EEXIST)
325                         die_errno(_("failed to create directory '%s'"), dest->buf);
326                 else if (stat(dest->buf, &buf))
327                         die_errno(_("failed to stat '%s'"), dest->buf);
328                 else if (!S_ISDIR(buf.st_mode))
329                         die(_("%s exists and is not a directory"), dest->buf);
330         }
331
332         strbuf_addch(src, '/');
333         src_len = src->len;
334         strbuf_addch(dest, '/');
335         dest_len = dest->len;
336
337         while ((de = readdir(dir)) != NULL) {
338                 strbuf_setlen(src, src_len);
339                 strbuf_addstr(src, de->d_name);
340                 strbuf_setlen(dest, dest_len);
341                 strbuf_addstr(dest, de->d_name);
342                 if (stat(src->buf, &buf)) {
343                         warning (_("failed to stat %s\n"), src->buf);
344                         continue;
345                 }
346                 if (S_ISDIR(buf.st_mode)) {
347                         if (de->d_name[0] != '.')
348                                 copy_or_link_directory(src, dest,
349                                                        src_repo, src_baselen);
350                         continue;
351                 }
352
353                 /* Files that cannot be copied bit-for-bit... */
354                 if (!strcmp(src->buf + src_baselen, "/info/alternates")) {
355                         copy_alternates(src, dest, src_repo);
356                         continue;
357                 }
358
359                 if (unlink(dest->buf) && errno != ENOENT)
360                         die_errno(_("failed to unlink '%s'"), dest->buf);
361                 if (!option_no_hardlinks) {
362                         if (!link(src->buf, dest->buf))
363                                 continue;
364                         if (option_local > 0)
365                                 die_errno(_("failed to create link '%s'"), dest->buf);
366                         option_no_hardlinks = 1;
367                 }
368                 if (copy_file_with_time(dest->buf, src->buf, 0666))
369                         die_errno(_("failed to copy file to '%s'"), dest->buf);
370         }
371         closedir(dir);
372 }
373
374 static void clone_local(const char *src_repo, const char *dest_repo)
375 {
376         if (option_shared) {
377                 struct strbuf alt = STRBUF_INIT;
378                 strbuf_addf(&alt, "%s/objects", src_repo);
379                 add_to_alternates_file(alt.buf);
380                 strbuf_release(&alt);
381         } else {
382                 struct strbuf src = STRBUF_INIT;
383                 struct strbuf dest = STRBUF_INIT;
384                 strbuf_addf(&src, "%s/objects", src_repo);
385                 strbuf_addf(&dest, "%s/objects", dest_repo);
386                 copy_or_link_directory(&src, &dest, src_repo, src.len);
387                 strbuf_release(&src);
388                 strbuf_release(&dest);
389         }
390
391         if (0 <= option_verbosity)
392                 fprintf(stderr, _("done.\n"));
393 }
394
395 static const char *junk_work_tree;
396 static const char *junk_git_dir;
397 static enum {
398         JUNK_LEAVE_NONE,
399         JUNK_LEAVE_REPO,
400         JUNK_LEAVE_ALL
401 } junk_mode = JUNK_LEAVE_NONE;
402
403 static const char junk_leave_repo_msg[] =
404 N_("Clone succeeded, but checkout failed.\n"
405    "You can inspect what was checked out with 'git status'\n"
406    "and retry the checkout with 'git checkout -f HEAD'\n");
407
408 static void remove_junk(void)
409 {
410         struct strbuf sb = STRBUF_INIT;
411
412         switch (junk_mode) {
413         case JUNK_LEAVE_REPO:
414                 warning("%s", _(junk_leave_repo_msg));
415                 /* fall-through */
416         case JUNK_LEAVE_ALL:
417                 return;
418         default:
419                 /* proceed to removal */
420                 break;
421         }
422
423         if (junk_git_dir) {
424                 strbuf_addstr(&sb, junk_git_dir);
425                 remove_dir_recursively(&sb, 0);
426                 strbuf_reset(&sb);
427         }
428         if (junk_work_tree) {
429                 strbuf_addstr(&sb, junk_work_tree);
430                 remove_dir_recursively(&sb, 0);
431                 strbuf_reset(&sb);
432         }
433 }
434
435 static void remove_junk_on_signal(int signo)
436 {
437         remove_junk();
438         sigchain_pop(signo);
439         raise(signo);
440 }
441
442 static struct ref *find_remote_branch(const struct ref *refs, const char *branch)
443 {
444         struct ref *ref;
445         struct strbuf head = STRBUF_INIT;
446         strbuf_addstr(&head, "refs/heads/");
447         strbuf_addstr(&head, branch);
448         ref = find_ref_by_name(refs, head.buf);
449         strbuf_release(&head);
450
451         if (ref)
452                 return ref;
453
454         strbuf_addstr(&head, "refs/tags/");
455         strbuf_addstr(&head, branch);
456         ref = find_ref_by_name(refs, head.buf);
457         strbuf_release(&head);
458
459         return ref;
460 }
461
462 static struct ref *wanted_peer_refs(const struct ref *refs,
463                 struct refspec *refspec)
464 {
465         struct ref *head = copy_ref(find_ref_by_name(refs, "HEAD"));
466         struct ref *local_refs = head;
467         struct ref **tail = head ? &head->next : &local_refs;
468
469         if (option_single_branch) {
470                 struct ref *remote_head = NULL;
471
472                 if (!option_branch)
473                         remote_head = guess_remote_head(head, refs, 0);
474                 else {
475                         local_refs = NULL;
476                         tail = &local_refs;
477                         remote_head = copy_ref(find_remote_branch(refs, option_branch));
478                 }
479
480                 if (!remote_head && option_branch)
481                         warning(_("Could not find remote branch %s to clone."),
482                                 option_branch);
483                 else {
484                         get_fetch_map(remote_head, refspec, &tail, 0);
485
486                         /* if --branch=tag, pull the requested tag explicitly */
487                         get_fetch_map(remote_head, tag_refspec, &tail, 0);
488                 }
489         } else
490                 get_fetch_map(refs, refspec, &tail, 0);
491
492         if (!option_mirror && !option_single_branch)
493                 get_fetch_map(refs, tag_refspec, &tail, 0);
494
495         return local_refs;
496 }
497
498 static void write_remote_refs(const struct ref *local_refs)
499 {
500         const struct ref *r;
501
502         struct ref_transaction *t;
503         struct strbuf err = STRBUF_INIT;
504
505         t = ref_transaction_begin(&err);
506         if (!t)
507                 die("%s", err.buf);
508
509         for (r = local_refs; r; r = r->next) {
510                 if (!r->peer_ref)
511                         continue;
512                 if (ref_transaction_create(t, r->peer_ref->name, r->old_sha1,
513                                            0, NULL, &err))
514                         die("%s", err.buf);
515         }
516
517         if (initial_ref_transaction_commit(t, &err))
518                 die("%s", err.buf);
519
520         strbuf_release(&err);
521         ref_transaction_free(t);
522 }
523
524 static void write_followtags(const struct ref *refs, const char *msg)
525 {
526         const struct ref *ref;
527         for (ref = refs; ref; ref = ref->next) {
528                 if (!starts_with(ref->name, "refs/tags/"))
529                         continue;
530                 if (ends_with(ref->name, "^{}"))
531                         continue;
532                 if (!has_sha1_file(ref->old_sha1))
533                         continue;
534                 update_ref(msg, ref->name, ref->old_sha1,
535                            NULL, 0, UPDATE_REFS_DIE_ON_ERR);
536         }
537 }
538
539 static int iterate_ref_map(void *cb_data, unsigned char sha1[20])
540 {
541         struct ref **rm = cb_data;
542         struct ref *ref = *rm;
543
544         /*
545          * Skip anything missing a peer_ref, which we are not
546          * actually going to write a ref for.
547          */
548         while (ref && !ref->peer_ref)
549                 ref = ref->next;
550         /* Returning -1 notes "end of list" to the caller. */
551         if (!ref)
552                 return -1;
553
554         hashcpy(sha1, ref->old_sha1);
555         *rm = ref->next;
556         return 0;
557 }
558
559 static void update_remote_refs(const struct ref *refs,
560                                const struct ref *mapped_refs,
561                                const struct ref *remote_head_points_at,
562                                const char *branch_top,
563                                const char *msg,
564                                struct transport *transport,
565                                int check_connectivity)
566 {
567         const struct ref *rm = mapped_refs;
568
569         if (check_connectivity) {
570                 if (transport->progress)
571                         fprintf(stderr, _("Checking connectivity... "));
572                 if (check_everything_connected_with_transport(iterate_ref_map,
573                                                               0, &rm, transport))
574                         die(_("remote did not send all necessary objects"));
575                 if (transport->progress)
576                         fprintf(stderr, _("done.\n"));
577         }
578
579         if (refs) {
580                 write_remote_refs(mapped_refs);
581                 if (option_single_branch)
582                         write_followtags(refs, msg);
583         }
584
585         if (remote_head_points_at && !option_bare) {
586                 struct strbuf head_ref = STRBUF_INIT;
587                 strbuf_addstr(&head_ref, branch_top);
588                 strbuf_addstr(&head_ref, "HEAD");
589                 create_symref(head_ref.buf,
590                               remote_head_points_at->peer_ref->name,
591                               msg);
592         }
593 }
594
595 static void update_head(const struct ref *our, const struct ref *remote,
596                         const char *msg)
597 {
598         const char *head;
599         if (our && skip_prefix(our->name, "refs/heads/", &head)) {
600                 /* Local default branch link */
601                 create_symref("HEAD", our->name, NULL);
602                 if (!option_bare) {
603                         update_ref(msg, "HEAD", our->old_sha1, NULL, 0,
604                                    UPDATE_REFS_DIE_ON_ERR);
605                         install_branch_config(0, head, option_origin, our->name);
606                 }
607         } else if (our) {
608                 struct commit *c = lookup_commit_reference(our->old_sha1);
609                 /* --branch specifies a non-branch (i.e. tags), detach HEAD */
610                 update_ref(msg, "HEAD", c->object.sha1,
611                            NULL, REF_NODEREF, UPDATE_REFS_DIE_ON_ERR);
612         } else if (remote) {
613                 /*
614                  * We know remote HEAD points to a non-branch, or
615                  * HEAD points to a branch but we don't know which one.
616                  * Detach HEAD in all these cases.
617                  */
618                 update_ref(msg, "HEAD", remote->old_sha1,
619                            NULL, REF_NODEREF, UPDATE_REFS_DIE_ON_ERR);
620         }
621 }
622
623 static int checkout(void)
624 {
625         unsigned char sha1[20];
626         char *head;
627         struct lock_file *lock_file;
628         struct unpack_trees_options opts;
629         struct tree *tree;
630         struct tree_desc t;
631         int err = 0;
632
633         if (option_no_checkout)
634                 return 0;
635
636         head = resolve_refdup("HEAD", RESOLVE_REF_READING, sha1, NULL);
637         if (!head) {
638                 warning(_("remote HEAD refers to nonexistent ref, "
639                           "unable to checkout.\n"));
640                 return 0;
641         }
642         if (!strcmp(head, "HEAD")) {
643                 if (advice_detached_head)
644                         detach_advice(sha1_to_hex(sha1));
645         } else {
646                 if (!starts_with(head, "refs/heads/"))
647                         die(_("HEAD not found below refs/heads!"));
648         }
649         free(head);
650
651         /* We need to be in the new work tree for the checkout */
652         setup_work_tree();
653
654         lock_file = xcalloc(1, sizeof(struct lock_file));
655         hold_locked_index(lock_file, 1);
656
657         memset(&opts, 0, sizeof opts);
658         opts.update = 1;
659         opts.merge = 1;
660         opts.fn = oneway_merge;
661         opts.verbose_update = (option_verbosity >= 0);
662         opts.src_index = &the_index;
663         opts.dst_index = &the_index;
664
665         tree = parse_tree_indirect(sha1);
666         parse_tree(tree);
667         init_tree_desc(&t, tree->buffer, tree->size);
668         if (unpack_trees(1, &t, &opts) < 0)
669                 die(_("unable to checkout working tree"));
670
671         if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
672                 die(_("unable to write new index file"));
673
674         err |= run_hook_le(NULL, "post-checkout", sha1_to_hex(null_sha1),
675                            sha1_to_hex(sha1), "1", NULL);
676
677         if (!err && option_recursive)
678                 err = run_command_v_opt(argv_submodule, RUN_GIT_CMD);
679
680         return err;
681 }
682
683 static int write_one_config(const char *key, const char *value, void *data)
684 {
685         return git_config_set_multivar(key, value ? value : "true", "^$", 0);
686 }
687
688 static void write_config(struct string_list *config)
689 {
690         int i;
691
692         for (i = 0; i < config->nr; i++) {
693                 if (git_config_parse_parameter(config->items[i].string,
694                                                write_one_config, NULL) < 0)
695                         die("unable to write parameters to config file");
696         }
697 }
698
699 static void write_refspec_config(const char *src_ref_prefix,
700                 const struct ref *our_head_points_at,
701                 const struct ref *remote_head_points_at,
702                 struct strbuf *branch_top)
703 {
704         struct strbuf key = STRBUF_INIT;
705         struct strbuf value = STRBUF_INIT;
706
707         if (option_mirror || !option_bare) {
708                 if (option_single_branch && !option_mirror) {
709                         if (option_branch) {
710                                 if (starts_with(our_head_points_at->name, "refs/tags/"))
711                                         strbuf_addf(&value, "+%s:%s", our_head_points_at->name,
712                                                 our_head_points_at->name);
713                                 else
714                                         strbuf_addf(&value, "+%s:%s%s", our_head_points_at->name,
715                                                 branch_top->buf, option_branch);
716                         } else if (remote_head_points_at) {
717                                 const char *head = remote_head_points_at->name;
718                                 if (!skip_prefix(head, "refs/heads/", &head))
719                                         die("BUG: remote HEAD points at non-head?");
720
721                                 strbuf_addf(&value, "+%s:%s%s", remote_head_points_at->name,
722                                                 branch_top->buf, head);
723                         }
724                         /*
725                          * otherwise, the next "git fetch" will
726                          * simply fetch from HEAD without updating
727                          * any remote-tracking branch, which is what
728                          * we want.
729                          */
730                 } else {
731                         strbuf_addf(&value, "+%s*:%s*", src_ref_prefix, branch_top->buf);
732                 }
733                 /* Configure the remote */
734                 if (value.len) {
735                         strbuf_addf(&key, "remote.%s.fetch", option_origin);
736                         git_config_set_multivar(key.buf, value.buf, "^$", 0);
737                         strbuf_reset(&key);
738
739                         if (option_mirror) {
740                                 strbuf_addf(&key, "remote.%s.mirror", option_origin);
741                                 git_config_set(key.buf, "true");
742                                 strbuf_reset(&key);
743                         }
744                 }
745         }
746
747         strbuf_release(&key);
748         strbuf_release(&value);
749 }
750
751 static void dissociate_from_references(void)
752 {
753         static const char* argv[] = { "repack", "-a", "-d", NULL };
754
755         if (run_command_v_opt(argv, RUN_GIT_CMD|RUN_COMMAND_NO_STDIN))
756                 die(_("cannot repack to clean up"));
757         if (unlink(git_path("objects/info/alternates")) && errno != ENOENT)
758                 die_errno(_("cannot unlink temporary alternates file"));
759 }
760
761 int cmd_clone(int argc, const char **argv, const char *prefix)
762 {
763         int is_bundle = 0, is_local;
764         struct stat buf;
765         const char *repo_name, *repo, *work_tree, *git_dir;
766         char *path, *dir;
767         int dest_exists;
768         const struct ref *refs, *remote_head;
769         const struct ref *remote_head_points_at;
770         const struct ref *our_head_points_at;
771         struct ref *mapped_refs;
772         const struct ref *ref;
773         struct strbuf key = STRBUF_INIT, value = STRBUF_INIT;
774         struct strbuf branch_top = STRBUF_INIT, reflog_msg = STRBUF_INIT;
775         struct transport *transport = NULL;
776         const char *src_ref_prefix = "refs/heads/";
777         struct remote *remote;
778         int err = 0, complete_refs_before_fetch = 1;
779
780         struct refspec *refspec;
781         const char *fetch_pattern;
782
783         packet_trace_identity("clone");
784         argc = parse_options(argc, argv, prefix, builtin_clone_options,
785                              builtin_clone_usage, 0);
786
787         if (argc > 2)
788                 usage_msg_opt(_("Too many arguments."),
789                         builtin_clone_usage, builtin_clone_options);
790
791         if (argc == 0)
792                 usage_msg_opt(_("You must specify a repository to clone."),
793                         builtin_clone_usage, builtin_clone_options);
794
795         if (option_single_branch == -1)
796                 option_single_branch = option_depth ? 1 : 0;
797
798         if (option_mirror)
799                 option_bare = 1;
800
801         if (option_bare) {
802                 if (option_origin)
803                         die(_("--bare and --origin %s options are incompatible."),
804                             option_origin);
805                 if (real_git_dir)
806                         die(_("--bare and --separate-git-dir are incompatible."));
807                 option_no_checkout = 1;
808         }
809
810         if (!option_origin)
811                 option_origin = "origin";
812
813         repo_name = argv[0];
814
815         path = get_repo_path(repo_name, &is_bundle);
816         if (path)
817                 repo = xstrdup(absolute_path(repo_name));
818         else if (!strchr(repo_name, ':'))
819                 die(_("repository '%s' does not exist"), repo_name);
820         else
821                 repo = repo_name;
822
823         /* no need to be strict, transport_set_option() will validate it again */
824         if (option_depth && atoi(option_depth) < 1)
825                 die(_("depth %s is not a positive number"), option_depth);
826
827         if (argc == 2)
828                 dir = xstrdup(argv[1]);
829         else
830                 dir = guess_dir_name(repo_name, is_bundle, option_bare);
831         strip_trailing_slashes(dir);
832
833         dest_exists = !stat(dir, &buf);
834         if (dest_exists && !is_empty_dir(dir))
835                 die(_("destination path '%s' already exists and is not "
836                         "an empty directory."), dir);
837
838         strbuf_addf(&reflog_msg, "clone: from %s", repo);
839
840         if (option_bare)
841                 work_tree = NULL;
842         else {
843                 work_tree = getenv("GIT_WORK_TREE");
844                 if (work_tree && !stat(work_tree, &buf))
845                         die(_("working tree '%s' already exists."), work_tree);
846         }
847
848         if (option_bare || work_tree)
849                 git_dir = xstrdup(dir);
850         else {
851                 work_tree = dir;
852                 git_dir = mkpathdup("%s/.git", dir);
853         }
854
855         atexit(remove_junk);
856         sigchain_push_common(remove_junk_on_signal);
857
858         if (!option_bare) {
859                 if (safe_create_leading_directories_const(work_tree) < 0)
860                         die_errno(_("could not create leading directories of '%s'"),
861                                   work_tree);
862                 if (!dest_exists && mkdir(work_tree, 0777))
863                         die_errno(_("could not create work tree dir '%s'"),
864                                   work_tree);
865                 junk_work_tree = work_tree;
866                 set_git_work_tree(work_tree);
867         }
868
869         junk_git_dir = git_dir;
870         if (safe_create_leading_directories_const(git_dir) < 0)
871                 die(_("could not create leading directories of '%s'"), git_dir);
872
873         set_git_dir_init(git_dir, real_git_dir, 0);
874         if (real_git_dir) {
875                 git_dir = real_git_dir;
876                 junk_git_dir = real_git_dir;
877         }
878
879         if (0 <= option_verbosity) {
880                 if (option_bare)
881                         fprintf(stderr, _("Cloning into bare repository '%s'...\n"), dir);
882                 else
883                         fprintf(stderr, _("Cloning into '%s'...\n"), dir);
884         }
885         init_db(option_template, INIT_DB_QUIET);
886         write_config(&option_config);
887
888         git_config(git_default_config, NULL);
889
890         if (option_bare) {
891                 if (option_mirror)
892                         src_ref_prefix = "refs/";
893                 strbuf_addstr(&branch_top, src_ref_prefix);
894
895                 git_config_set("core.bare", "true");
896         } else {
897                 strbuf_addf(&branch_top, "refs/remotes/%s/", option_origin);
898         }
899
900         strbuf_addf(&value, "+%s*:%s*", src_ref_prefix, branch_top.buf);
901         strbuf_addf(&key, "remote.%s.url", option_origin);
902         git_config_set(key.buf, repo);
903         strbuf_reset(&key);
904
905         if (option_reference.nr)
906                 setup_reference();
907         else if (option_dissociate) {
908                 warning(_("--dissociate given, but there is no --reference"));
909                 option_dissociate = 0;
910         }
911
912         fetch_pattern = value.buf;
913         refspec = parse_fetch_refspec(1, &fetch_pattern);
914
915         strbuf_reset(&value);
916
917         remote = remote_get(option_origin);
918         transport = transport_get(remote, remote->url[0]);
919         transport_set_verbosity(transport, option_verbosity, option_progress);
920
921         path = get_repo_path(remote->url[0], &is_bundle);
922         is_local = option_local != 0 && path && !is_bundle;
923         if (is_local) {
924                 if (option_depth)
925                         warning(_("--depth is ignored in local clones; use file:// instead."));
926                 if (!access(mkpath("%s/shallow", path), F_OK)) {
927                         if (option_local > 0)
928                                 warning(_("source repository is shallow, ignoring --local"));
929                         is_local = 0;
930                 }
931         }
932         if (option_local > 0 && !is_local)
933                 warning(_("--local is ignored"));
934         transport->cloning = 1;
935
936         if (!transport->get_refs_list || (!is_local && !transport->fetch))
937                 die(_("Don't know how to clone %s"), transport->url);
938
939         transport_set_option(transport, TRANS_OPT_KEEP, "yes");
940
941         if (option_depth)
942                 transport_set_option(transport, TRANS_OPT_DEPTH,
943                                      option_depth);
944         if (option_single_branch)
945                 transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, "1");
946
947         if (option_upload_pack)
948                 transport_set_option(transport, TRANS_OPT_UPLOADPACK,
949                                      option_upload_pack);
950
951         if (transport->smart_options && !option_depth)
952                 transport->smart_options->check_self_contained_and_connected = 1;
953
954         refs = transport_get_remote_refs(transport);
955
956         if (refs) {
957                 mapped_refs = wanted_peer_refs(refs, refspec);
958                 /*
959                  * transport_get_remote_refs() may return refs with null sha-1
960                  * in mapped_refs (see struct transport->get_refs_list
961                  * comment). In that case we need fetch it early because
962                  * remote_head code below relies on it.
963                  *
964                  * for normal clones, transport_get_remote_refs() should
965                  * return reliable ref set, we can delay cloning until after
966                  * remote HEAD check.
967                  */
968                 for (ref = refs; ref; ref = ref->next)
969                         if (is_null_sha1(ref->old_sha1)) {
970                                 complete_refs_before_fetch = 0;
971                                 break;
972                         }
973
974                 if (!is_local && !complete_refs_before_fetch)
975                         transport_fetch_refs(transport, mapped_refs);
976
977                 remote_head = find_ref_by_name(refs, "HEAD");
978                 remote_head_points_at =
979                         guess_remote_head(remote_head, mapped_refs, 0);
980
981                 if (option_branch) {
982                         our_head_points_at =
983                                 find_remote_branch(mapped_refs, option_branch);
984
985                         if (!our_head_points_at)
986                                 die(_("Remote branch %s not found in upstream %s"),
987                                     option_branch, option_origin);
988                 }
989                 else
990                         our_head_points_at = remote_head_points_at;
991         }
992         else {
993                 if (option_branch)
994                         die(_("Remote branch %s not found in upstream %s"),
995                                         option_branch, option_origin);
996
997                 warning(_("You appear to have cloned an empty repository."));
998                 mapped_refs = NULL;
999                 our_head_points_at = NULL;
1000                 remote_head_points_at = NULL;
1001                 remote_head = NULL;
1002                 option_no_checkout = 1;
1003                 if (!option_bare)
1004                         install_branch_config(0, "master", option_origin,
1005                                               "refs/heads/master");
1006         }
1007
1008         write_refspec_config(src_ref_prefix, our_head_points_at,
1009                         remote_head_points_at, &branch_top);
1010
1011         if (is_local)
1012                 clone_local(path, git_dir);
1013         else if (refs && complete_refs_before_fetch)
1014                 transport_fetch_refs(transport, mapped_refs);
1015
1016         update_remote_refs(refs, mapped_refs, remote_head_points_at,
1017                            branch_top.buf, reflog_msg.buf, transport, !is_local);
1018
1019         update_head(our_head_points_at, remote_head, reflog_msg.buf);
1020
1021         transport_unlock_pack(transport);
1022         transport_disconnect(transport);
1023
1024         if (option_dissociate)
1025                 dissociate_from_references();
1026
1027         junk_mode = JUNK_LEAVE_REPO;
1028         err = checkout();
1029
1030         strbuf_release(&reflog_msg);
1031         strbuf_release(&branch_top);
1032         strbuf_release(&key);
1033         strbuf_release(&value);
1034         junk_mode = JUNK_LEAVE_ALL;
1035
1036         free(refspec);
1037         return err;
1038 }